Aspects of reproduction and diet of the Australian endemic skate Dipturus polyommata (Ogilby) (Elasmobranchii: Rajidae), by-catch of a commercial prawn trawl fishery

The Australian endemic skate Dipturus polyommata collected from by-catch of a benthic prawn fishery off southern Queensland was examined to provide information on reproduction and diet. Morphological relationships of total length (LT) to disc width and LT to mass were estimated. Size at birth was estimated at c. 100-110 mm and size at first feeding at c. 105-110 mm LT. Size at 50% maturity (LT50 and 95% CI) was 321 (305-332) and 300 (285-306) mm LT for females and males, respectively. Size at first maturity corresponded to 87.7% of observed maximum size in females (366 mm LT) and 87.5% in males (343 mm L T). Two females, representing 18.2% of mature females sampled in the austral winter were each carrying two egg cases. Descriptions of egg cases are given. Diet described by the index of relative importance as a percentage (%IRI) was predominantly crustacean based with carid shrimps (53.64%) and penaeoid prawns (23.30%) the most significant prey groups. Teleosts (11.72%), gammarid amphipods (5.31%) and mysids (4.72%) were also important to the diet of the species, while a further six prey groups made only a minor contribution to diet (1.31%). An ontogenetic change was evident between the diets of immature and mature skates. Immature animals fed more extensively on carids and amphipods and mature animals on penaeoids, teleosts and mysids.

Survival and reproduction of Tribolium castaneum (Herbst), Rhyzopertha dominica (F.) and Sitophilus oryzae (L.) following periods of starvation

This study determined the starvation tolerance of Tribolium castaneum (Herbst), Rhyzopertha dominica (F.) and Sitophilus oryzae (L.) in terms of both adult survival and reproduction, the impact of starvation on reproduction not having been studied before. Experiments were conducted at 30°C and 55% or 70% r.h. using a laboratory strain and a field strain of each species. The number of progeny was a better indicator of the impact of starvation on a species than adult survival. Tribolium castaneum was the most tolerant species, requiring up to 35 d starvation before no progeny were produced. Rhyzopertha dominica and S. oryzae required up to 8 d starvation before no progeny were produced. The results suggest that hygiene will have a greater impact on populations of S. oryzae and R. dominica than T. castaneum.

Reproduction of an autographed portrait of Ludwig Bamberger seated holding paper Portraits; Men

Signed Ludwig Bamberger

Reproduction of portrait of field chaplain Rabbi Dr. Sali Levi Military; World War I; Portraits

Feldrabbiner Dr. Sali Lewi, Breslau

Reproduction of portrait of Ida Dehmel, founder of Gedak Portraits; Women

Verso: Ida Dehmel als sie 1927 die Gedak gruendete

Reproduction of Richard Dehmel reading with his wife Ida Dehmel nee Auerbach sitting across from him, early in their marriage; Parkstrasse, Hamburg Portraits; Couples

Verso: Erste Wohnung Parkstrasse Fruehzeit der Ehe 1901

Reproduction of painted portrait of Marcus Elias Marcus, age 76. Portraits Men

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Reproduction of cover illustration of the book "Kinder-Turnen in Haus" by Fritz Strube. Sports

The drawing is modeled after Elizabeth Gottschalk (later Krakauer)

Freddy Gottschalk making a bridge over his sister Ursula Gottschalk in a reproduction of an illustration for the book "Kinder-Turnen in Haus" by Fritz Strube. Sports

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Kurt and Hal Gottschalk exercising with a medicine ball in a reproduction of an illustration for the book "Kinder-Turnen in Haus" by Fritz Strube. Sports

Digital Image